Known conventional flush toilets in which waste is discharged by flushing with flush water supplied from a flush water source have included those such as set forth in Patent Document 1 (Japanese Patent Unexamined Publication No. 2016-41879), for example, wherein in a connecting surface for connecting a rising wall portion forming the inside perimeter surface of the rim on a toilet main unit bowl, in order to limit the accumulation of urine at the connecting surface around the center portion in the left-right direction of the front area of the bowl where urine is particularly prone to strike, the vertical curvature radius of the connecting portion is maximal at the left-right center of the bowl front area, and becomes gradually smaller toward the left and right sides.
However, in the conventional flush toilet of the above-described Patent Document 1, the inside perimeter side of the bowl rim has an edgeless shape. This presents the problem that flush water spouted into and circulating in the bowl, as well as urine, can splash outside the bowl.
Also, in the above-described conventional flush toilet, there is no boundary or shelf, etc. between the vertical wall area inside the bowl and the circulating area in which flush water circulates. This raises the risk that, with the change in curvature radius in the vertical direction of the connecting surface, in particular, circulating water will expand on the vertical wall portion side, or that circulating water will drop on the bowl side without completing a full revolution, so that flushing is not sufficiently completed.